1. Field of the Invention
The present invention generally relates to a circuit board and manufacturing method thereof, in particular, to a circuit board having electromagnetic shielding effect and a manufacturing method thereof.
2. Description of Related Art
Generally speaking, a circuit board for carrying or electrically connecting a plurality of electronic components is formed by alternately stacking a plurality of patterned conductive layers and a plurality of dielectric layers. The patterned circuit layers are defined by the copper foil after performing a photolithographic process. The dielectric layers are respectively disposed between two adjacent patterned circuit layers, for isolating the patterned circuit layers. Moreover, various electronic components (e.g. active or passive components) may be disposed on the surface of the circuit board, and circuit layers of the circuit board may be used to achieve the purpose of electrical signal propagation. However, since the technical requirement of the signal propagation frequency transmitting by the circuit layers becomes increasingly high, the electromagnetic interference and noises between any two circuit layers gradually aggravates.